In a plea agreement with prosecutors, O'Donnell admitted to asking 10 people, including employees of his law firm and at least one relative, to each make donations of $2,000. He then reimbursed them, thereby masking that he was the source of the funds. The attorney agreed to serve six months in federal prison for the "conduit contribution" charges, in addition to a $20,000 fine and 200 hours of community service.

The case stems from contributions made to John Edwards' 2004 presidential bid. In a news release, the U.S. attorney's office said the campaign, which is not mentioned by name in court filings, is not suspected of having had knowledge of the illicit contributions.

"We are pleased with today's resolution," said Brian J. O'Neill, O'Donnell's lawyer, noting that the final decision is still in the judge's discretion. "From the outset of this case, we have been seeking to get the charges reduced to misdemeanors."

U.S. Atty. Andre Birotte said in a statement that O'Donnell, a business litigator who has run for the House of Representatives in the past, should have been "well aware" of federal election laws but "chose to circumvent the laws designed to maintain transparency and shed light on the campaign process."

O'Donnell, 64, who was a lead plaintiff's attorney for flood victims of Hurricane Katrina suing the U.S. government, previously pleaded no contest in 2006 to misdemeanor state court charges of using a false name in making political contributions in the 2001 mayoral campaign of James K. Hahn. O'Donnell was sentenced to probation and ordered to pay more than $155,000 in fines and penalties in that case.

Earlier this year, the California State Bar ordered that O'Donnell's license be suspended for 60 days and that he be placed on probation for two years for the conduct leading to his conviction. The agency found that O'Donnell's actions involved moral turpitude and other misconduct.

Federal prosecutors had initially insisted that any plea agreement involve a felony conviction, which would have ended O'Donnell's legal career in California, sources told The Times in 2008 at the time of the indictment. A prosecutor on Thursday declined to discuss the timing or terms of the plea.

In his federal case, O'Donnell is scheduled to appear for a sentencing hearing on Nov. 7 before U.S. District Judge S. James Otero, who will decide whether to accept the plea agreement.